1.CE,CCC,ISO 2.water in the tank is the heat storage 3.the water we use from the copper ... absorb solar energy,and heats the water inside the tube,hot water rises,cold water flows down). It differs from ... can purify the water),so it can supply hot water with high quality, clean and even drinkable.2.And as ... copper coil transfer the heat rapidly,so it can ensure that the water is ...